Controls Namespace

ComboBox Component

The ComboBox control is used to display data in a drop-down combo box. By default, the ComboBox control appears in two parts: the top part is a text box that allows the user to type a list item. The second part is a list box that displays a list of items from which the user can select one.

The PureComponents ComboBox control is used to display data in a drop-down combo box. By default, the ComboBox control appears in two parts: the top part is a text box that allows the user to type a list item. The second part is a list box that displays a list of items from which the user can select one.

The SelectedIndex property returns an integer value that corresponds to the selected list item. You can programmatically change the selected item by changing the SelectedIndex value in code; the corresponding item in the list will appear in the text box portion of the combo box. If no item is selected, the SelectedIndex value is -1. If the first item in the list is selected, then the SelectedIndex value is 0. The SelectedItem property is similar to SelectedIndex, but returns the item itself, usually a string value. The Items.Count property reflects the number of items in the list, and the value of the Items.Count property is always one more than the largest possible SelectedIndex value because SelectedIndex is zero-based.

To add or delete items in a ComboBox control, use the Items.Add, Items.Insert, Items.Clear or Items.Remove method. Alternatively, you can add items to the list by using the Items property in the designer.

Appearance

The appearance of the combo box is influenced by the ComboBoxStyle class setting. Style contains another subclass ListStyle, which determines the drop-down appearance in the list. This contains subclasses ItemStyle.

In properties, which determine the color, you can also use Transparent color. That way you can achieve interesting result.

Masks

The use of masks is useful when you want to adjust the text you are entering to specific format. The example can be phone number. Enter to property Mask string (999)-000-0000. This mask defines phone number used in The United States. Area code is optional. If users do not want to enter the optional characters, they can either enter spaces or place the mouse pointer directly at the position in the mask represented by the first 0.